import chrriis.dj.nativeswing.swtimpl.NativeComponent;
import chrriis.dj.nativeswing.swtimpl.NativeInterface;
import chrriis.dj.nativeswing.swtimpl.components.JWebBrowser;
import chrriis.dj.nativeswing.swtimpl.components.WebBrowserAdapter;
import chrriis.dj.nativeswing.swtimpl.components.WebBrowserEvent;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class ScreenShot extends JPanel {
    private static final long serialVersionUID = 1L;
    final static public String LS = System.getProperty("line.separator", "\n");
    final static StringBuffer jsDimension;//以javascript脚本获得网页全屏后大小

    static {
        jsDimension = new StringBuffer();
        jsDimension.append("var width = 0;").append(LS);
        jsDimension.append("var height = 0;").append(LS);
        jsDimension.append("if(document.documentElement) {").append(LS);
        jsDimension.append("  width = Math.max(width, document.documentElement.scrollWidth);").append(LS);
        jsDimension.append("  height = Math.max(height, document.documentElement.scrollHeight);").append(LS);
        jsDimension.append("}").append(LS);
        jsDimension.append("if(self.innerWidth) {").append(LS);
        jsDimension.append("  width = Math.max(width, self.innerWidth);").append(LS);
        jsDimension.append("  height = Math.max(height, self.innerHeight);").append(LS);
        jsDimension.append("}").append(LS);
        jsDimension.append("if(document.body.scrollWidth) {").append(LS);
        jsDimension.append("  width = Math.max(width, document.body.scrollWidth);").append(LS);
        jsDimension.append("  height = Math.max(height, document.body.scrollHeight);").append(LS);
        jsDimension.append("}").append(LS);
        jsDimension.append("return width + ':' + height;");
    }

    public ScreenShot(final String url, final int maxWidth, final int maxHeight) {
        super(new BorderLayout());
        JPanel webBrowserPanel = new JPanel(new BorderLayout());
        final String fileName = "e:/" + System.currentTimeMillis() + ".jpg";
        final JWebBrowser webBrowser = new JWebBrowser(null);
        webBrowser.setBarsVisible(false);
        webBrowser.navigate(url);
        webBrowserPanel.add(webBrowser, BorderLayout.CENTER);
        add(webBrowserPanel, BorderLayout.CENTER);
        JPanel panel = new JPanel(new FlowLayout(FlowLayout.CENTER, 4, 4));

        webBrowser.addWebBrowserListener(new WebBrowserAdapter() {
            // 监听加载进度
            public void loadingProgressChanged(WebBrowserEvent e) {
                // 当加载完毕时
                if (e.getWebBrowser().getLoadingProgress() == 100) {
                    String result = (String) webBrowser.executeJavascriptWithResult(jsDimension.toString());
                    int index = result == null ? -1 : result.indexOf(":");
                    NativeComponent nativeComponent = webBrowser.getNativeComponent();
                    Dimension originalSize = nativeComponent.getSize();
                    Dimension imageSize = new Dimension(Integer.parseInt(result.substring(0, index)), Integer.parseInt(result.substring(index + 1)));
                    imageSize.width = Math.max(originalSize.width, imageSize.width + 50);
                    imageSize.height = Math.max(originalSize.height, imageSize.height + 50);
                    nativeComponent.setSize(imageSize);
                    BufferedImage image = new BufferedImage(imageSize.width, imageSize.height, BufferedImage.TYPE_INT_RGB);
                    nativeComponent.paintComponent(image);
                    nativeComponent.setSize(originalSize);
                    // 当网页超出目标大小时
                    if (imageSize.width > maxWidth || imageSize.height > maxHeight) {
                        //截图部分图形
                        image = image.getSubimage(0, 0, maxWidth, maxHeight);
                        /*此部分为使用缩略图
                        int width = image.getWidth(), height = image.getHeight();
						AffineTransform tx = new AffineTransform();
						tx.scale((double) maxWidth / width, (double) maxHeight / height);
						AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
						image = op.filter(image, null); //缩小
						*/
                    }
                    try {
                        ImageIO.write(image, "jpg", new File(fileName));
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                    System.exit(0);
                }
            }
        }
        );
        add(panel, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        NativeInterface.open();
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                // SWT组件转Swing组件，不初始化父窗体将无法启动webBrowser
                JFrame frame = new JFrame("以DJ组件保存指定网页截图");
                // 加载google，最大保存为640x480的截图
                frame.getContentPane().add(new ScreenShot("https://www.taobao.com/", 960, 860), BorderLayout.CENTER);
                frame.setSize(800, 600);
                // 仅初始化，但不显示
                frame.invalidate();
                frame.pack();
                frame.setVisible(false);
            }
        });
        NativeInterface.runEventPump();
    }
}
